Тема доклада:

Mapping atomic motions with ultrabright electrons: Realization of the chemists’ gedanken experiment

Докладчик:

R. J. Dwayne Miller

The Max Planck Inst. for the Structure and Dynamics of Matter; The Hamburg Centre for Ultrafast Imaging; Departments of Chemistry and Physics, University of Toronto

Аннотация:

Prof. R. J. Dwayne Miller has published over 200 research articles, one book, and several reviews. He has pioneered the development of both coherent multidimensional spectroscopy methods, associated ultrafast laser technology, and introduced the concept of using ultrabright electron sources to probe structural dynamics. The electron sources developed by his group are sufficiently bright to literally light up atomic motions in real time. He and his group were the first to capture atomic motions during the defining moments of chemistry – to directly observe the very essence of chemistry. This work accomplished one of the dream experiments in science, to bring the chemists’ collective gedanken experiment of chemistry to direct observation.

One of the grand challenges in science is to watch atomic motions on the primary timescales of structural transitions, i.e. to watch atoms move in real time. This prospect would provide a direct observation of the very essence of chemistry and the central unifying concept of transition states that links chemistry to biology. This experiment has been referred to as "making the molecular movie". Due to the extraordinary requirements for simultaneous spatial and temporal resolution, it was thought to be an impossible quest and has been previously discussed in the context of the purest form of a gedanken experiment. With the recent development of ultrabright electron sources capable of literally lighting up atomic motions, this experiment has been realized (Siwick et al. Science 2003). The first studies focused on relatively simple systems. Further advances in source brightness allowed a bunch of new experiments on reaction dynamics to atomic inspection. Recent studies of formally a photoinduced charge transfer process in charge ordered organic systems has directly observed the most strongly coupled modes that stabilize the charge separated state (Gao et al Nature 2013).

These developments will be discussed in the context of developing the necessary technology to directly observe the structure-function correlation in biomolecules - to give the most fundamental (atomic) basis for understanding biological systems at the molecular level.

Проход на территорию ИСАН по предварительной записи по тел. (495)851-02-21 или е-mail: isan@isan.troitsk.ru